OPTIMAL CONTROL METHODS FOR TOKAMAK REACTORS

THE OBJECTIVE OF THIS PROJECT IS TO APPLY OPTIMAL CONTROL METHODOLOGY TO FUSION REACTOR SYSTEMS. CURRENT FUSION EXPERIMENTAL DEVICES SUCH AS JET AND TFR EMPLOY FEEDBACK CONTROL SYSTEMS FOR SINGLE SUBSYSTEMS. HOWEVER, FUTURE FUSION REACTORS AND EXPERIMENTAL TOKAMAKS SUCH AS ITER WILL REQUIRE AN INTEGRATED CONTROL WHICH COMBINES THE OVERALL SYSTEM. NOT ONLY IS SUCH A SYSTEM REQUIRED FOR NORMAL OPERATION, BUT IT IS ESSENTIAL FOR SAFETY IN CASE OF A DISRUPTION OR OTHER MALFUNCTION. WE PROPOSE TO ADOPT A NEW "SELF-TUNING" ADAPTIVE-TYPE CONTROL METHODOLOGY THAT WAS ORIGINALLY DEVELOPED FOR USE WITH PWR-TYPE FISSION REACTORS. THIS APPROACH IS ESPECIALLYWELL SUITED TO COMPLEX SYSTEMS SUCH AS FUSION WHERE THERE ARE CONSIDERABLE UNCERTAINTIES IN THE GOVERNING PARAMETRIC RELATIONS SUCH AS THE PLASMA CONFINEMENT SCALING LAW. TO HANDLE FAST TRANSIENTS, DISRUPTIONS, ETC., A NEW "ANTICIPATORY" METHODOLOGY BASED ON ARTIFICIAL INTELLIGENCE TECHNIQUES WILL ALSO BE INCORPORATED. SEVERAL AUXILIARY STUDIES ARE ALSO REQUIRED. FIRST, VARIOUSMETHODS TO CONTROL THE PLASMA BURN (HEATING/FUELING, IMPURITY INJECTION, VARIABLE RIPPLE, ETC.) WILL BE COMPARED AND A "BEST" APPROACH AND ALTERNATE SELECTED. SECOND, THE ARRAY OF DIAGNOSTIC SENSORS NEEDED FOR CONTROL WILL BE DEFINED. ALTERNATE ARRAYS WILL BE USED TO STUDY DIFFERENCES BETWEEN GLOBAL AND PROFILE DEPENDENT PLASMA CONTROL. FINALLY, AN OVERALL FUSION PLANT COMPUTER MODEL, INCLUDING DYNAMICS, WILL BE DEVELOPED TO TEST THE CONTROL SYSTEMS.